//===- CrashDebugger.cpp - Debug compilation crashes ----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
//
// This file defines the bugpoint internals that narrow down compilation crashes
//
//===----------------------------------------------------------------------===//
#include "BugDriver.h"
-#include "SystemUtils.h"
+#include "ListReducer.h"
+#include "llvm/Constant.h"
+#include "llvm/iTerminators.h"
#include "llvm/Module.h"
-#include "llvm/Bytecode/Writer.h"
#include "llvm/Pass.h"
+#include "llvm/PassManager.h"
+#include "llvm/SymbolTable.h"
+#include "llvm/Type.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Bytecode/Writer.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "Support/FileUtilities.h"
#include <fstream>
+#include <set>
-#if 0
class DebugCrashes : public ListReducer<const PassInfo*> {
BugDriver &BD;
public:
// the "Kept" passes fail when run on the output of the "removed" passes. If
// we return true, we update the current module of bugpoint.
//
- virtual bool doTest(const std::vector<ElTy> &Removed,
- const std::vector<ElTy> &Kept) {
- return BD.runPasses(Kept);
- }
+ virtual TestResult doTest(std::vector<const PassInfo*> &Removed,
+ std::vector<const PassInfo*> &Kept);
};
-#endif
-/// debugCrash - This method is called when some pass crashes on input. It
-/// attempts to prune down the testcase to something reasonable, and figure
-/// out exactly which pass is crashing.
-///
-bool BugDriver::debugCrash() {
- std::cout << "\n*** Debugging optimizer crash!\n";
+DebugCrashes::TestResult
+DebugCrashes::doTest(std::vector<const PassInfo*> &Prefix,
+ std::vector<const PassInfo*> &Suffix) {
+ std::string PrefixOutput;
+ Module *OrigProgram = 0;
+ if (!Prefix.empty()) {
+ std::cout << "Checking to see if these passes crash: "
+ << getPassesString(Prefix) << ": ";
+ if (BD.runPasses(Prefix, PrefixOutput))
+ return KeepPrefix;
-#if 0
- // Reduce the list of passes which causes the optimizer to crash...
- DebugCrashes(*this).reduceList(PassesToRun);
-#endif
-
- unsigned LastToPass = 0, LastToCrash = PassesToRun.size();
- while (LastToPass != LastToCrash) {
- unsigned Mid = (LastToCrash+LastToPass+1) / 2;
- std::vector<const PassInfo*> P(PassesToRun.begin(),
- PassesToRun.begin()+Mid);
- std::cout << "Checking to see if the first " << Mid << " passes crash: ";
-
- if (runPasses(P))
- LastToCrash = Mid-1;
- else
- LastToPass = Mid;
- }
+ OrigProgram = BD.Program;
- // Make sure something crashed. :)
- if (LastToCrash >= PassesToRun.size()) {
- std::cerr << "ERROR: No passes crashed!\n";
- return true;
+ BD.Program = BD.ParseInputFile(PrefixOutput);
+ if (BD.Program == 0) {
+ std::cerr << BD.getToolName() << ": Error reading bytecode file '"
+ << PrefixOutput << "'!\n";
+ exit(1);
+ }
+ removeFile(PrefixOutput);
}
- // Calculate which pass it is that crashes...
- const PassInfo *CrashingPass = PassesToRun[LastToCrash];
+ std::cout << "Checking to see if these passes crash: "
+ << getPassesString(Suffix) << ": ";
- std::cout << "\n*** Found crashing pass '-" << CrashingPass->getPassArgument()
- << "': " << CrashingPass->getPassName() << "\n";
-
- // Compile the program with just the passes that don't crash.
- if (LastToPass != 0) { // Don't bother doing this if the first pass crashes...
- std::vector<const PassInfo*> P(PassesToRun.begin(),
- PassesToRun.begin()+LastToPass);
- std::string Filename;
- std::cout << "Running passes that don't crash to get input for pass: ";
- if (runPasses(P, Filename)) {
- std::cerr << "ERROR: Running the first " << LastToPass
- << " passes crashed this time!\n";
- return true;
- }
+ if (BD.runPasses(Suffix)) {
+ delete OrigProgram; // The suffix crashes alone...
+ return KeepSuffix;
+ }
- // Assuming everything was successful, we now have a valid bytecode file in
- // OutputName. Use it for "Program" Instead.
- delete Program;
- Program = ParseInputFile(Filename);
+ // Nothing failed, restore state...
+ if (OrigProgram) {
+ delete BD.Program;
+ BD.Program = OrigProgram;
+ }
+ return NoFailure;
+}
+
+class ReduceCrashingFunctions : public ListReducer<Function*> {
+ BugDriver &BD;
+public:
+ ReduceCrashingFunctions(BugDriver &bd) : BD(bd) {}
- // Delete the file now.
- removeFile(Filename);
+ virtual TestResult doTest(std::vector<Function*> &Prefix,
+ std::vector<Function*> &Kept) {
+ if (!Kept.empty() && TestFuncs(Kept))
+ return KeepSuffix;
+ if (!Prefix.empty() && TestFuncs(Prefix))
+ return KeepPrefix;
+ return NoFailure;
}
+
+ bool TestFuncs(std::vector<Function*> &Prefix);
+};
- PassesToRun.clear();
- PassesToRun.push_back(CrashingPass);
+bool ReduceCrashingFunctions::TestFuncs(std::vector<Function*> &Funcs) {
+ // Clone the program to try hacking it apart...
+ Module *M = CloneModule(BD.Program);
+
+ // Convert list to set for fast lookup...
+ std::set<Function*> Functions;
+ for (unsigned i = 0, e = Funcs.size(); i != e; ++i) {
+ Function *CMF = M->getFunction(Funcs[i]->getName(),
+ Funcs[i]->getFunctionType());
+ assert(CMF && "Function not in module?!");
+ Functions.insert(CMF);
+ }
- return debugPassCrash(CrashingPass);
-}
+ std::cout << "Checking for crash with only these functions:";
+ unsigned NumPrint = Funcs.size();
+ if (NumPrint > 10) NumPrint = 10;
+ for (unsigned i = 0; i != NumPrint; ++i)
+ std::cout << " " << Funcs[i]->getName();
+ if (NumPrint < Funcs.size())
+ std::cout << "... <" << Funcs.size() << " total>";
+ std::cout << ": ";
-/// CountFunctions - return the number of non-external functions defined in the
-/// module.
-static unsigned CountFunctions(Module *M) {
- unsigned N = 0;
+ // Loop over and delete any functions which we aren't supposed to be playing
+ // with...
for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
- if (!I->isExternal())
- ++N;
- return N;
+ if (!I->isExternal() && !Functions.count(I))
+ DeleteFunctionBody(I);
+
+ // Try running the hacked up program...
+ std::swap(BD.Program, M);
+ if (BD.runPasses(BD.PassesToRun)) {
+ delete M; // It crashed, keep the trimmed version...
+
+ // Make sure to use function pointers that point into the now-current
+ // module.
+ Funcs.assign(Functions.begin(), Functions.end());
+ return true;
+ }
+ delete BD.Program; // It didn't crash, revert...
+ BD.Program = M;
+ return false;
}
-/// debugPassCrash - This method is called when the specified pass crashes on
-/// Program as input. It tries to reduce the testcase to something that still
-/// crashes, but it smaller.
+
+/// ReduceCrashingBlocks reducer - This works by setting the terminators of all
+/// terminators except the specified basic blocks to a 'ret' instruction, then
+/// running the simplify-cfg pass. This has the effect of chopping up the CFG
+/// really fast which can reduce large functions quickly.
///
-bool BugDriver::debugPassCrash(const PassInfo *Pass) {
- EmitProgressBytecode("passinput");
- bool Reduced = false, AnyReduction = false;
+class ReduceCrashingBlocks : public ListReducer<BasicBlock*> {
+ BugDriver &BD;
+public:
+ ReduceCrashingBlocks(BugDriver &bd) : BD(bd) {}
+
+ virtual TestResult doTest(std::vector<BasicBlock*> &Prefix,
+ std::vector<BasicBlock*> &Kept) {
+ if (!Kept.empty() && TestBlocks(Kept))
+ return KeepSuffix;
+ if (!Prefix.empty() && TestBlocks(Prefix))
+ return KeepPrefix;
+ return NoFailure;
+ }
+
+ bool TestBlocks(std::vector<BasicBlock*> &Prefix);
+};
- if (CountFunctions(Program) > 1) {
- // Attempt to reduce the input program down to a single function that still
- // crashes. Do this by removing everything except for that one function...
- //
- std::cout << "\n*** Attempting to reduce the testcase to one function\n";
+bool ReduceCrashingBlocks::TestBlocks(std::vector<BasicBlock*> &BBs) {
+ // Clone the program to try hacking it apart...
+ Module *M = CloneModule(BD.Program);
+
+ // Convert list to set for fast lookup...
+ std::set<BasicBlock*> Blocks;
+ for (unsigned i = 0, e = BBs.size(); i != e; ++i) {
+ // Convert the basic block from the original module to the new module...
+ Function *F = BBs[i]->getParent();
+ Function *CMF = M->getFunction(F->getName(), F->getFunctionType());
+ assert(CMF && "Function not in module?!");
- for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I)
- if (!I->isExternal()) {
- // Extract one function from the module...
- Module *M = extractFunctionFromModule(I);
+ // Get the mapped basic block...
+ Function::iterator CBI = CMF->begin();
+ std::advance(CBI, std::distance(F->begin(), Function::iterator(BBs[i])));
+ Blocks.insert(CBI);
+ }
- // Make the function the current program...
- std::swap(Program, M);
-
- // Find out if the pass still crashes on this pass...
- std::cout << "Checking function '" << I->getName() << "': ";
- if (runPass(Pass)) {
- // Yup, it does, we delete the old module, and continue trying to
- // reduce the testcase...
- delete M;
-
- Reduced = AnyReduction = true;
- break;
- }
+ std::cout << "Checking for crash with only these blocks:";
+ unsigned NumPrint = Blocks.size();
+ if (NumPrint > 10) NumPrint = 10;
+ for (unsigned i = 0, e = NumPrint; i != e; ++i)
+ std::cout << " " << BBs[i]->getName();
+ if (NumPrint < Blocks.size())
+ std::cout << "... <" << Blocks.size() << " total>";
+ std::cout << ": ";
+
+ // Loop over and delete any hack up any blocks that are not listed...
+ for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
+ for (Function::iterator BB = I->begin(), E = I->end(); BB != E; ++BB)
+ if (!Blocks.count(BB) && !isa<ReturnInst>(BB->getTerminator())) {
+ // Loop over all of the successors of this block, deleting any PHI nodes
+ // that might include it.
+ for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI)
+ (*SI)->removePredecessor(BB);
+
+ // Delete the old terminator instruction...
+ BB->getInstList().pop_back();
- // This pass didn't crash on this function, try the next one.
- delete Program;
- Program = M;
+ // Add a new return instruction of the appropriate type...
+ const Type *RetTy = BB->getParent()->getReturnType();
+ ReturnInst *RI = new ReturnInst(RetTy == Type::VoidTy ? 0 :
+ Constant::getNullValue(RetTy));
+ BB->getInstList().push_back(RI);
}
- if (CountFunctions(Program) > 1) {
- std::cout << "\n*** Couldn't reduce testcase to one function.\n"
- << " Attempting to remove individual functions.\n";
- std::cout << "XXX Individual function removal unimplemented!\n";
+ // The CFG Simplifier pass may delete one of the basic blocks we are
+ // interested in. If it does we need to take the block out of the list. Make
+ // a "persistent mapping" by turning basic blocks into <function, name> pairs.
+ // This won't work well if blocks are unnamed, but that is just the risk we
+ // have to take.
+ std::vector<std::pair<Function*, std::string> > BlockInfo;
+
+ for (std::set<BasicBlock*>::iterator I = Blocks.begin(), E = Blocks.end();
+ I != E; ++I)
+ BlockInfo.push_back(std::make_pair((*I)->getParent(), (*I)->getName()));
+
+ // Now run the CFG simplify pass on the function...
+ PassManager Passes;
+ Passes.add(createCFGSimplificationPass());
+ Passes.add(createVerifierPass());
+ Passes.run(*M);
+
+ // Try running on the hacked up program...
+ std::swap(BD.Program, M);
+ if (BD.runPasses(BD.PassesToRun)) {
+ delete M; // It crashed, keep the trimmed version...
+
+ // Make sure to use basic block pointers that point into the now-current
+ // module, and that they don't include any deleted blocks.
+ BBs.clear();
+ for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) {
+ SymbolTable &ST = BlockInfo[i].first->getSymbolTable();
+ SymbolTable::iterator I = ST.find(Type::LabelTy);
+ if (I != ST.end() && I->second.count(BlockInfo[i].second))
+ BBs.push_back(cast<BasicBlock>(I->second[BlockInfo[i].second]));
}
+ return true;
}
+ delete BD.Program; // It didn't crash, revert...
+ BD.Program = M;
+ return false;
+}
+
+/// debugCrash - This method is called when some pass crashes on input. It
+/// attempts to prune down the testcase to something reasonable, and figure
+/// out exactly which pass is crashing.
+///
+bool BugDriver::debugCrash() {
+ bool AnyReduction = false;
+ std::cout << "\n*** Debugging optimizer crash!\n";
+
+ // Reduce the list of passes which causes the optimizer to crash...
+ unsigned OldSize = PassesToRun.size();
+ DebugCrashes(*this).reduceList(PassesToRun);
- if (Reduced) {
- EmitProgressBytecode("reduced-function");
- Reduced = false;
+ std::cout << "\n*** Found crashing pass"
+ << (PassesToRun.size() == 1 ? ": " : "es: ")
+ << getPassesString(PassesToRun) << "\n";
+
+ EmitProgressBytecode("passinput");
+
+ // See if we can get away with nuking all of the global variable initializers
+ // in the program...
+ if (Program->gbegin() != Program->gend()) {
+ Module *M = CloneModule(Program);
+ bool DeletedInit = false;
+ for (Module::giterator I = M->gbegin(), E = M->gend(); I != E; ++I)
+ if (I->hasInitializer()) {
+ I->setInitializer(0);
+ I->setLinkage(GlobalValue::ExternalLinkage);
+ DeletedInit = true;
+ }
+
+ if (!DeletedInit) {
+ delete M; // No change made...
+ } else {
+ // See if the program still causes a crash...
+ std::cout << "\nChecking to see if we can delete global inits: ";
+ std::swap(Program, M);
+ if (runPasses(PassesToRun)) { // Still crashes?
+ AnyReduction = true;
+ delete M;
+ std::cout << "\n*** Able to remove all global initializers!\n";
+ } else { // No longer crashes?
+ delete Program; // Restore program.
+ Program = M;
+ std::cout << " - Removing all global inits hides problem!\n";
+ }
+ }
+ }
+
+ // Now try to reduce the number of functions in the module to something small.
+ std::vector<Function*> Functions;
+ for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I)
+ if (!I->isExternal())
+ Functions.push_back(I);
+
+ if (Functions.size() > 1) {
+ std::cout << "\n*** Attempting to reduce the number of functions "
+ "in the testcase\n";
+
+ OldSize = Functions.size();
+ ReduceCrashingFunctions(*this).reduceList(Functions);
+
+ if (Functions.size() < OldSize) {
+ EmitProgressBytecode("reduced-function");
+ AnyReduction = true;
+ }
}
- // FIXME: This should attempt to delete entire basic blocks at a time to speed
- // up convergence...
+ // Attempt to delete entire basic blocks at a time to speed up
+ // convergence... this actually works by setting the terminator of the blocks
+ // to a return instruction then running simplifycfg, which can potentially
+ // shrinks the code dramatically quickly
+ //
+ if (!DisableSimplifyCFG) {
+ std::vector<BasicBlock*> Blocks;
+ for (Module::iterator I = Program->begin(), E = Program->end(); I != E; ++I)
+ for (Function::iterator FI = I->begin(), E = I->end(); FI != E; ++FI)
+ Blocks.push_back(FI);
+ ReduceCrashingBlocks(*this).reduceList(Blocks);
+ }
+ // FIXME: This should use the list reducer to converge faster by deleting
+ // larger chunks of instructions at a time!
unsigned Simplification = 4;
do {
--Simplification;
std::cout << "\n*** Attempting to reduce testcase by deleting instruc"
<< "tions: Simplification Level #" << Simplification << "\n";
- // Now that we have deleted the functions that are unneccesary for the
- // program, try to remove instructions that are not neccesary to cause the
+ // Now that we have deleted the functions that are unnecessary for the
+ // program, try to remove instructions that are not necessary to cause the
// crash. To do this, we loop through all of the instructions in the
// remaining functions, deleting them (replacing any values produced with
// nulls), and then running ADCE and SimplifyCFG. If the transformed input
// Find out if the pass still crashes on this pass...
std::cout << "Checking instruction '" << I->getName() << "': ";
- if (runPass(Pass)) {
+ if (runPasses(PassesToRun)) {
// Yup, it does, we delete the old module, and continue trying to
// reduce the testcase...
delete M;
- Reduced = AnyReduction = true;
+ AnyReduction = true;
goto TryAgain; // I wish I had a multi-level break here!
}
} while (Simplification);
// Try to clean up the testcase by running funcresolve and globaldce...
- if (AnyReduction) {
- std::cout << "\n*** Attempting to perform final cleanups: ";
- Module *M = performFinalCleanups();
- std::swap(Program, M);
+ std::cout << "\n*** Attempting to perform final cleanups: ";
+ Module *M = performFinalCleanups();
+ std::swap(Program, M);
- // Find out if the pass still crashes on the cleaned up program...
- if (runPass(Pass)) {
- // Yup, it does, keep the reduced version...
- delete M;
- Reduced = AnyReduction = true;
- } else {
- delete Program; // Otherwise, restore the original module...
- Program = M;
- }
+ // Find out if the pass still crashes on the cleaned up program...
+ if (runPasses(PassesToRun)) {
+ // Yup, it does, keep the reduced version...
+ delete M;
+ AnyReduction = true;
+ } else {
+ delete Program; // Otherwise, restore the original module...
+ Program = M;
}
- if (Reduced) {
+ if (AnyReduction)
EmitProgressBytecode("reduced-simplified");
- Reduced = false;
- }
return false;
}